1. Field of the Invention
The present invention relates to a binocular and, more particularly, to a binocular in which right and left optical axes are adjustable.
2. Related Background Art
A binocular has a pair of right and left objective optical systems, and a pair of right and left eyepiece units that integrally hold erecting optical systems comprised of erecting prisms and mirrors and eyepiece optical systems. In the binocular, all or some of the groups of the pair of right and left objective optical systems are held integrally, or are held such that they move together without changing a gap between them when the binocular is in use. A mechanism and method of adjusting the right and left optical axes of the binocular are available as follows.
(1) As is proposed in Japanese Patent Laid-Open No. 8-211303, in a binocular in which all groups of right and left objective lenses are integrally held by a fixing portion and an erecting optical system and eyepiece optical system serve together to form an eyepiece unit, an arrangement and method fix objective optical systems by moving and adjusting them in a direction perpendicular to an optical axis.
(2) As is proposed in Japanese Patent Laid-Open Nos. 10-319325 and 2000-56351, in a binocular in which all groups of right and left objective optical systems are integrally held by a movable portion and an erecting optical system and eyepiece optical system serve together to form an eyepiece unit, an arrangement and method fix one objective optical system while fixing the other objective optical system by moving and adjusting it in a direction perpendicular to an optical axis.
(3) As is proposed in Japanese Patent Laid-Open No. 10-213733, in a binocular in which right and left objective lenses are held such that the distance between them is not changed by eye-to-eye width adjustment but are rotatable and both the right and left objective lenses form telescopes, an arrangement and method rotate the respective telescope portions entirely about the optical axes of objective optical systems as the centers for eye-to-eye width adjustment, and adjust and move the directions of rotary axes for this rotation, thereby inclining the respective telescope portions entirely.
(4) As is proposed in Japanese Patent Laid-Open No. 9-281411 (U.S. Pat. No. 5,903,387), in a so-called xe2x80x9cthin binocularxe2x80x9d in which the distance between the objective optical systems changes during eye-to-eye width adjustment (when the binocular is in use) and an erecting optical system and eyepiece optical system are integrated, an arrangement and method adjust the objective optical system and eyepiece optical system by moving one of them vertically while moving the other horizontally to be independent of each other.
(5) As is proposed in Japanese Patent Laid-Open No. 9-304704, in a xe2x80x9cthin binocularxe2x80x9d, an arrangement and method adjust right and left erecting optical system units by moving one of them vertically whole moving the other horizontally to be independent of each other.
(6) As an optical axis adjusting mechanism and method that have been used since a long time ago in a xe2x80x9cmid-foldable binocularxe2x80x9d or the like, an arrangement and method set the outer shape of the lens frame of an objective lens to be eccentric from the optical axis of the lens, fix and arrange a spacer having an eccentric amount almost equal to that of the lens frame around the mirror frame, adjust and set the eccentric amount of the mirror frame from the optical axis with a rotary phase with respect to the spacer, and adjust and set the optical axis of the spacer in the eccentric direction with a rotary phase with respect to a fixing portion (accepting portion).
In these conventional optical axis adjusting mechanisms and methods, the relationship in parallel degree between the optical axis of the objective optical system and that of the eyepiece optical system can be maintained the same before and after adjustment.
Of these conventional optical axis adjusting mechanisms and methods for the binocular as described above, in (1) and (2), to fix the objective optical systems during or after adjustment, the fixing operation must be performed in the vicinity of the optical axis. Hence, the fixing adjustment and adjustment checking should not be performed across the optical path. This makes the operation difficult to perform.
In (2), the objective optical systems themselves, which are to be adjusted, are fixed to an objective base that moves during focal point adjustment, or are fixed to an objective lens holder which is part of an image shaking correction mechanism. To perform adjustment or fixing after adjustment, unless the objective lens fixing portions are securely fixed by using a tool or the like, adjustment or fixing cannot be performed. This is cumbersome.
In (3), the first lens barrel in the vicinity of the objective optical system is rotated during use (eye-to-eye width adjustment). Therefore, it is difficult to arrange a mechanism for imparting an additional function such as image shaking correction or automatic focus adjustment to the front half of the binocular.
In both the so-called xe2x80x9cthin binocularxe2x80x9d of (4) and (5) and the so-called xe2x80x9cmid-foldable binocularxe2x80x9d of (6), the right and left objective optical systems are not integrated, and undesirably move horizontally during eye-to-eye width adjustment. Such binocular may serve all right as a conventional binocular. When, however, a mechanism for an additional function is to be particularly added, large limitations are imposed in terms of space and function.
It is, therefore, an object of the present invention to provide a binocular in which right and left optical axes can be adjusted easily without causing any problem when providing an additional function for enlarging the observation performance of the binocular or the application range of the binocular in addition to the main function of a conventional binocular.
In order to achieve the above object, a binocular according to the present invention comprises:
a pair of objective optical systems;
a pair of eyepiece units for integrally holding erecting optical systems and eyepiece optical systems; and
a holding member having a first holding portion for holding one of the pair of eyepiece units and a second holding portion for holding the other one of the pair of eyepiece units,
wherein the holding member is deformed such that the pair of eyepiece units have a predetermined positional relationship.
A binocular according to the present invention comprises:
a pair of objective optical systems;
a pair of eyepiece units for integrally holding erecting optical systems and eyepiece optical systems; and
a holding member having a first holding portion for holding one of the pair of eyepiece units and a second holding portion for holding the other one of the pair of eyepiece units,
wherein the holding member can be deformed such that the pair of eyepiece units have a predetermined positional relationship.
A method of manufacturing a binocular according to the present invention comprises the steps of:
holding one of a pair of optical units with a first holding portion of a holding member, and holding the other one of the pair of optical units with a second holding portion of the holding member; and
deforming the holding member, thereby adjusting a positional relationship between the optical units.
Furthermore, a method of manufacturing a binocular comprises the steps of:
holding one of a pair of optical units with a first holding portion of a holding member, and holding the other one of the pair of optical units with a second holding portion of the holding member;
connecting a bent portion of the first holding portion and a bent portion of the second holding portion through a connecting member;
setting a connecting position of the connecting member and the bent portion of the first holding portion to be eccentric by rotating an eccentric roller, so the holding member is deformed, thereby adjusting a positional relationship between the optical units.
The practical applications of the present invention will become apparent in the detailed description of the invention which follows.